Refractory-lined blast furnace tuyere



p 1967 F. K. ARMOUR ETAL REFRACTORY-LINED BLAST FURNACE TUYERIE 2Sheets-Sheet Filed June FIG.|

INVENTORS 24 FHA/VA A. ARMOUR R05RT E. TOUZ/IL //V 26- 38 :3 K cl FIG. 1

2 Sheets-Sheet .51,

1 Om v @N F. K.- ARMOUR ETAL REFRACTORY-LINED BLAST FURNACE TUYERE Sept.12, 1967 Filed June INVENTORS FHA/VA K; ARMOUR P055 BY R7 5. TOUZ/M/IVATTORNEYS United States Patent Office 3,341,188 REFRACTORY-LINED BLASTFURNACE TUYERE Frank K. Armour, Olympia Fields, 111., and Robert E.

Touzalin, Aurora, Ohio, assignors to Interlake Steel Corporation, acorporation of New York Filed June 3, 1965, Ser. No. 460,896 16 Claims.(Cl. 266-41) ABSTRACT OF THE DISCLOSURE A tuyere for use in a blastfurnace comprising a sleevelike member having inner and outer side wallsdefining a cooling chamber therebetween, the inner wall defining anaxially extending passageway for receiving a fluid blast therethrough.The inner wall having an interior circumferentially continuous recessextending for a major portion of the length of the blast passageway andan insulating material disposed in a flush relationship in the recess soas not to interfere with the blast in the passageway.

This invention relates in general to furnace tuyeres and moreparticularly to a blast furnace tuyere which has increased service lifeand provides for high efficiency in the operation of the furnace.

In present day practice, a blast furnace is generally equipped withtuyeres made of metal, such as for instance copper and the tuyeres aregenerally provided with an arrangement for cooling the same such as forinstance by being hollow whereby cooling water can circulate inside thetuyere, while a hot air blast from a blast furnace stove or the likepasses through the blast passageway through the central portion of thetuyere. There has also been proposed the use of heat resistant insertsfor insertion into the blast passageway of the tuyeres, in an effort toincrease the service life thereof. However, such insert arrangementshave not been entirely satisfactory in that they obstruct the hot airblast passageway through the tuyere, thereby changing the blowingcharacteristics of the tuyere design during the blast furnace operation.

The present invention provides an improved arrangement of tuyere for afurnace which embodies a sleeve or insert member of heat resistant andlow heat conducting material which is recessed into the tuyere so thatthe hot air blast passageway through the tuyere is not obstructed, andtherefore the blast penetration into the furnace is maintained at theoriginally designed values. The invention also provides a tuyere whichhas a greatly increased service life as compared to heretofore knownarrangements of tuyeres, as well as novel methods of making the tuyeresof the invention.

Accordingly, an object of the invention is to provide a novel tuyere fora furnace.

Another object of the invention is to provide a novel tuyere for a blastfurnace including an insert member of heat resistant material which isrecessed into the tuyeres so as to not obstruct the blast passageway andwhich is operable to reduce the amount of heat transfer to the coolantused for cooling the tuyere, and which will increase the service life ofthe tuyere without affecting the blast characteristics of the furnace.

A more specific object of the invention is to provide a tuyere for afurnace with refractory insert recessed into the tuyere so as to notobstruct the hot air blast passageway through the tuyere, and whichinsert serves to insulate the tuyere from the hot air blast, and'wherein there is provided a metallic surfacing covering the insert inthe hot air blast passageway.

Another object is to provide novel methods of manufacture for insulatedtuyeres.

Other objects and advantages of the invention will be 3,341,188 PatentedSept. 12, 1967 apparent from the following description taken inconjunction with the accompanying drawings wherein:

FIG. 1 is a fragmentary, diagrammatic, sectional view of a blast furnacehaving a tuyere arrangement of the invention embodied therewith;

FIG. 2 is an enlarged outer end view of the tuyere construction;

FIG. 3 is a fragmentary, sectional elevational view of a tuyereconstructed in accordance with the invention;

FIG. 4 is a view similar to FIG. 3 but showing another embodiment of theinvention;

FIG. 5 is an enlarged, fragmentary, sectional elevational view generallysimilar to those of FIGS. 3 and 4, but showing a further embodiment ofthe invention;

FIG. 6 is a View similar to FIG. 5, but showing another embodiment ofthe invention.

Referring now to FIG. 1, hot air from a blast furnace stove (not shown)may pass through the hot blast main 10, bustle pipe 12, bootlegs 14,blow pipes 16, and tuyeres 18, and into the furnace 20. Molten iron andslag, the result of the blast furnace operation collects on the hearth22 of the furnace in the conventional manner.

The tuyere members may each comprise a tapered, generally cylindricallike article having an axial passageway 24 extending therethrough andthrough which the hot air blast passes into the furnace. The tuyere maybe cored or hollowed out to form a chamber as at 26, thereby providinginner and outer sidewalls 26a, 26b, said chamber being operable forcooling the tuyere member by circulation of a coolant therethroughduring operation of the blast furnace. The coolant may be introduced andwithdrawn from the chamber 26 as by means of pipes 27 and associatedports 27a in the outer end wall of the tuyere.

The inner end or nose 28 of the tuyere may be of generally solidconstruction, and there may be provided an interior cooling ring 30extending rearwardly from the nose and in the conventional manner.

In accordance with the invention, the tuyere is provided with acircumferentially extending recess 32 in wall 26a, which terminates asat 32a in spaced relationship to the inner end extremity of the tuyere,and terminates as at 32b in spaced relationship to the outer endextremity of the tuyere. As can be seen from FIG. 3, this recess alsoterminates rearwardly of the inner end of the coolant chamber 26. Intothis recess is placed a refractory material 34 which is of low heatconductivity and high abrasion resistance. A satisfactory material hasbeen found to be a chemically bonded high alumina refractory, and whichis commercially known as Resco Cast AA-22 manufactured by the RefractorySpecialties Company of Norristown, Pa. Such material may be troweledinto place in recess 32 in the tuyere and formed and maintained there bymeans of a core pattern until it has set. After it has set for a periodof, for instance, from four to 24 hours, the refractory material is hardenough for use.

It will be noted that the castable material 34 does not project into thepassageway 24 of the tuyere but merely forms a continuation of the airblast surfaces 36 of the tuyere, such blast passageway 24 through thetuyere tapering from the outer end of the tuyere to the inner end of thetuyere as shown.

A temperature resistant metallic surface such as a stainless steelsurface may then be applied to the blast opening 24 through the tuyere,as by means of spraying the metal thereon. A layer thickness ofstainless steel of approximately 0.015 inch has been found to besatisfactoryfThe temperature resistant metallic surface preferablyextends from the inner to the outer end of the tuyere, thus completelycoating the blast opening 24 and the insulating member 34.

It will be seen therefore that the layer of castable refractory materialor insulating member 34 which may be of a thickness of approximately /2inch, is maintained within the tuyere without affecting in any way theair velocity and blast characteristics at the nose of the tuyere. Therecessed arrangement also protects the insulating layer 34 fromattrition due to high temperature radiation and molten slag in thefurnace, and the spacing of the insulating member 34 from the inner endof the tuyere which may be approximately 2% inches for a inch longtuyere, protects the insulating member from the high temperatures andslag action in the furnace.

Referring now to FIG. 4 there is shown another embodiment of theinvention in which the tuyere maybe of the same general type as'aforedescribed. However, in this arrangement there is provided a metalliner member 38 which is recessed into the tuyere as shown so as to notobstruct the blast passageway 24 through the tuyere. Behind the metalliner 38 there is provided a layer of castable refractory material 34which may be of the type known as Resco Cast RS-3-35 manufactured by theRefractory Specialties Company of Norristown, Pa., of a thickness ofapproximately 3 inch. Because the material 34' is protected by the metalliner 38, it can be of low strength and does not have to be abrasionresistant as does the heretofore mentioned material 34. The metallicliner 38 is preferably of a high temperature alloy and may berepresented commercially by an alloy known as Hastelloy Alloy X producedby the Stellite Division of the Union Carbide Corporation. It comprisesapproximately 18 /2% iron, 22% chomium, 9% molybdenum and 45% nickel.Such alloy has excellent high temperature strength and oxidationresistance up to approximately 2200 F.

The castable material 34, which is likewise recessed into the tuyere asshown, could be inserted into place in recess 40, and then the liner 38which can be fabricated with one or more longitudinal joints 39, can beinstalled in the tuyere and expanded into place, and then welded alongthe longitudinal seam into an integral liner. Or the liner 38 may beprovided with holes 39a therein, and then inserted into the tuyere andexpanded into place and welded, and then the castable insulatingmaterial 34' may be inserted into the recess 40 in the tuyere throughsuch holes, and permitted to harden. The sections of the liner 38removed to form the holes 39a may then be inserted back into place inthe holes and welded into an integral liner.

Referring now to FIG. 5, there is shown another embodiment of tuyerewherein the tuyere proper is of generally similar construction as theFIG, 3 embodiment except that the recess 44 in the tuyere extends allthe way to the outer end thereof, so that the insulating liner member 46can be preformed and then inserted from the outer end of the tuyere intoplace.

Such insulating member 46 can be secured in place by any suitabletemperature resistant refractory slurry or paste 47, to bond the linerto the inner wall 26a of the tuyere. A suitable refractory paste hasbeen found to be that commercially identified as 8-820 made by theGlasrock Products, Inc. of Atlanta, Ga. There are many other suitablerefractory mortars that could be utilized such as that known as Super#3000, made by the Refractory and Insulating Corporation of PortKennedy, Pa., and Resco Set 33 made by the aforementioned RefractorySpecialties Company of Norr-istown, Pa. The outer end of the insulatingmember 46 is preferably tapered as at 48 so as to provide clearance forthe blow pipe 50 coacting with the outer end of the tuyere.

Referring now to FIG. 6, there is shown a further embodiment, wherein aliner.38' which may be generally similar to the liner 38 of the FIG. 4embodiment, is inserted in the recess 44 in the tuyere. In thisarrangement, the liner does not have to be slotted longitudinallythereof since it can be inserted from the rear or open end of the tuyeretogether with the insulating member 46. Such liner and refractoryinsulating member 46' can be held in place by a suitable one of theaforementioned refractory pastes coacting between the tuyere proper andthe insulating member 46' and the liner 38 to hold them together in anintegral unit against movement axially and rotatively of the tuyere.

From the foregoing discussion and the accompanying drawings, it will beseen that the invention provides a novel tuyere arrangement for a blastfurnace which includes an insulating member or section which is operableto reduce the amount of heat transfer to the coolant used for coolingthe tuyere, and which insulating insert is recessed Within the tuyere soas not to interfere with the blast opening through the tuyere and thuswill not change the operating blast characteristics of the furnace. Theinvention also provides novel methods of providing a tuyere with aninsulating insert associated therewith and in a manner to give longservice life characteristics to the tuyere.

The terms and expressions which have been used are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of any of thefeatures shown or described, or portions thereof, and it is recognizedthat various modifications are possible within the scope of theinvention claimed.

We claim:

1. A tuyere comprising, a sleeve-like member having inner and outer sidewalls defining a cooling chamber therebetween, said inner wall definingan axially extending blast passageway through the tuyere, said innerwall having an interior circumferential recess therein extending for amajor portion of the length of said blast passageway, insulating meansdisposed in said recess so as not to project out into said passagewaypast the other defining surfaces of said passageway, said insulatingmeans being recessed radially from said other defining surfaces of saidpassageway and including a metallic liner disposed in said recessradially inwardly with respect to said insulating means, said linerbeing generally flushed with said other defining surfaces of saidpassageway so as not to interfere with the blast characteristics of thetuyere, and including opening means in said liner, closure meansinserted in said opening means, and means attaching said closure meansto the remainder of the liner.

2. A tuyere in accordance with claim 1 wherein said liner is initiallysevered longitudinally thereof and when assembled in the tuyere isexpanded into place to form a longitudinal seam, and weld means closingsaid longitudinal seam of the liner.

3. A tuyere in accordance with claim 1 wherein said liner overlaps saidinsulating means in a direction lengthwise thereof, but in rearwardlyspaced relationship to the forwardmost extremity of said coolingchamber.

4. A tuyere in accordance with claim 1 wherein said liner is comprisedof a high temperature alloy possessing high temperature strength andoxidation resistance.

5. A tuyere in accordance with claim 4 wherein said alloy consistsessentially of approximately 18% iron, 27% chromium, 9% molybdenum, and45% nickel.

6. A tuyere for use in a blast furnace comprising, a generallycylindrical sleeve-like member having inner and outer ends and outer andinner walls defining a cooling chamber therebetwen, the exterior surfaceof said inner wall defining an axially extending blast passageway whichtapers convergently in a direction toward said inner end, said innerwall having an interior circumferentially continuous recess extendingfor a major portion of the length of said blast passageway, said recessspaced axially inwardly from the inner end of said sleeve-like memberand rearwardly of the forwardmost extremity of said cooling chamber, anda refractory insulating material disposed to completely fill saidrecess, said refractory insulating material having a smooth,uninterrupted interior surface which is disposed in flush relationshipwith the exterior surface of said rear wall so as not to interfere withthe blast characteristics through said tuyere.

7 A t y e in accordance with claim 6, wherein said refractory insulatingmaterial is a preformed one-piece member, and heat resistant adhesivemeans holding said preformed member in said recess.

8. A tuyere in accordance with claim 6, including a metallic linerdisposed in said recess radially inwardly of said insulating material,said incsulating material being recessed radially from said blastpassageway and said liner being disposed in flush relationship with saidblast passageway throughout its length.

9. A tuyere in accordance with claim 8, wherein said metallic lineroverlaps said insulating material in a direction lengthwise thereof, butin rearwardly spaced relationship relative to the forwardmost extremityof said cooling chamber.

10. A tuyere in accordance with claim 9, wherein said insulatingmaterial and said metallic liner are spaced axially inwardly from therear end of said sleeve-like member.

11. A tuyere in accordance with claim 7, wherein the end of thepreformed member adjacent the outer end of said sleeve-like member istapered outwardly toward said inner wall in a direction toward the outerend of said sleeve-like member and is spaced inwardly in an axialdirection from the outer end of said sleeve-like member.

12. A tuyere in accordance with claim 7, wherein said recess opens ontothe outer end of said sleeve-like member, and said preformed memberbeing tapered at the end adjacent the outer end of said sleeve-likemember and terminating axially inwardly from the outer end of saidsleeve-like member.

13. A tuyere in accordance 'with claim 6 wherein said insulating meansis comprised of a castable refractory material.

14. A tuyere in accordance with claim 6 wherein said blast passagewayhas a layer of a heat resistant met-a1 thereon, said layer covering saidinsulating means.

15. A tuyere in accordance with claim 14 wherein said layer is in theform of a coating having a thickness of approximately 0.015 inch.

16. A tuyere in accordance with claim 6 wherein said tuyere has athickened nose portion and wherein said recess commences rearwardly ofsaid thickened nose portion and rearwardly of the forwardmost extremityof said cooling chamber, and a cooling ring in said chamber extendingrearwardly from said nose portion.

References Cited UNITED STATES PATENTS 2,023,025 12/ 1935 McKee 266-412,497,000 2/ 1950 Johnson 266-41 3,031,178 4/ 1962 White 26641 3,043,5787/1962 Cohn 266-41 3,061,300 10/ 1962 Schultz 26641 J. SPENCEROVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner.

1. A TUYERE COMPRISING, A SLEEVE-LIKE MEMBER HAVING INNER AND OUTER SIDEWALLS DEFINING A COOLING CHAMBER THEREBETWEEN, SAID INNER WALL DEFININGAN AXIALLY EXTENDING BLAST PASSAGEWAY THROUGH THE TUYERE, SAID INNERWALL HAVING AN INTERIOR CIRCUMFERENTIAL RECESS THEREIN EXTENDING FOR AMAJOR PORTION OF THE LENGTH OF SAID BLAST PASSAGEWAY, INSULATING MEANSDISPOSED IN SAID RECESS SO AS NOT TO PROJECT OUT INTO SAID PASSAGEWAYPAST THE OTHER DEFINING SURFACES OF SAID PASSAGEWAY, SAID INSULATINGMEANS BEING RECESSED RADIALLY FROM SAID OTHER DEFINING SURFACES OF SAIDPASSAGEWAY AND INCLUDING A METALLIC LINER DISPOSED IN SAID RECESSRADIALLY INWARDLY WITH RESPECT TO SAID INSULATING MEANS, SAID LINERBEING GENERALLY FLUSHED WITH SAID OTHER DEFINING SURFACES OF SAIDPASSAGEWAY SO AS NOT TO INTERFERE WITH THE BLAST CHARACTERISTICS OF THETUYERE, AND INCLUDING OPENING MEANS IN SAID LINER, CLOSURE MEANSINSERTED IN SAID OPENING MEANS, AND MEANS ATTACHING SAID CLOSURE MEANSTO THE REMAINDER OF THE LINER.